How he died: Unexplained. The episode was an unplanned addition to Glee's fifth season after Cory Monteith, the actor who played him, died unexpectedly shortly before production on the season began.
How it made us feel: Devastated. Watching Monteith's real-life girlfriend Lea Michele, whom he met on set, and his former co-stars act out their grief on screen was truly difficult to watch. The emotions were very, very real, and no matter how you felt about Glee at the time, the episode allowed the actors and fans alike to grieve.
What it meant for the show: In the two episodes that followed "The Quarterback," which centered on Finn's passing, the audience saw both Kurt and Rachel struggle a bit with feeling normal again. They both ended up getting tattoos as a way to deal with the pain. Unfortunately for Kurt, because of a typo, his reads, "It's get better." But indeed, it does.